Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: waltergmw on February 16, 2012, 12:45:48 PM

Title: FTTC performance estimates & current configuration
Post by: waltergmw on February 16, 2012, 12:45:48 PM
Gentlefolk,

I have recently been following some anomalies on a couple of lines on THGI Guildford destined to have FTTC soon.

When this saga started all lines on two FTTC enabled cabinets indicated that services were available.
They then became only available on February 29 and March 30 respectively, suggesting that FTTC line card provisioning was inadequate.

Perhaps more interestingly when checking on this site:-

https://www.btwholesale.com/includes/adsl/main.html

one of the line's results included the wording:-


Quote
Your cabinet is planned to have WBC FTTC by 30th March 2012. Our test also indicates that your line currently supports a fibre technology with an estimated WBC FTTC Broadband where consumers have received downstream line speed of 64.1Mbps and upstream line speed of 20Mbps.

Quite obviously that statement was factually incorrect. It has now been replaced by this wording:-


Quote
Your cabinet is planned to have WBC FTTC by 30th March 2012. Our test also indicates that your line currently supports a fibre technology with an estimated WBC FTTC Broadband where consumers have received downstream line speed of 40Mbps and upstream line speed of 10Mbps.

Unless I'm mistaken this suggests that current services on VDSL profile 17a are actually capped at 39.999 Kbps.
If so, I suspect many excited consumers will be disappointed when their imperfect lines will not achieve 2 * 39.999 Kbps after the "Up to 80 Mbps" commercial arrangements are in place.

Kind regards,
Walter

Title: Re: FTTC performance estimates & current configuration
Post by: Bald_Eagle1 on February 16, 2012, 06:02:29 PM
Hi Walter,


Unless I'm mistaken this suggests that current services on VDSL profile 17a are actually capped at 39.999 Kbps.
If so, I suspect many excited consumers will be disappointed when their imperfect lines will not achieve 2 * 39.999 Kbps after the "Up to 80 Mbps" commercial arrangements are in place.


That is indeed the case.
It should also be noted that the 39999 Kbps is a MAXIMUM Sync speed.
Some connections are capped by BT's Fibre Centre at a lower Sync speed (for reasons currently unknown) & some are capped by DLM due to line quality/error counts, frequency of disconnections etc.

It appears that for a short while the BT estimating programs were reporting "Attainable Rates", rather than the current capped speed of 40Mb.

A few users on selected exchanges are currently taking part in the 80Mb/20Mb trials.
These users have seen variable speeds between 50Mb & 80Mb, dependent mainly on distance from the fibre cabinet.

At this stage it is unknown what speed estimates would be for lines currently unable to achieve 40Mb from the capped service once the 80/20 service is rolled out.

I believe the ISP ADSL24 has been trialing the 80/20 service for some users who were previously achieving sync speeds between 15Mb & 40Mb.
I have not yet seen any results from these lower speed trialists, but it would be interesting to see the effect of an attempt to squirt 80Mb down a D-side cable that cannot currently achieve anywhere near the current 40Mb cap level.

Paul.